Air or water craft propulsion



Feb. 1, 1938. c. M. LEE

AIR OR WATER CRAFT PROPULSION I Filed June 50, 1957 Patented Feb. 1,1938 UNITED STATES PATENT OFFICE Application June 30',

4 Claims.

The propeller construction herein disclosed is made for the purpose ofdriving air or water craft by means of static pressure of the sustainingmedium in back of the craft. It thus, with airplanes, has the functionof removing air from in advance of the driven object rather than drivingthe craft by a screw action through the air, which latter is the commonpractice of this day. In water it does not waste work in the manner ofscrew propulsion by building bow waves through sheer pressure.

A purpose of the invention is to decisively increase the speed of aircraft or water craft over that which may be had by screw propulsionmethods now in general use. A further purpose of the invention is toprovide a propeller blade arrangement whereby the differences inpressures on opposite sides of rotating blades counteract centrifugalforce and enable the use of a lighter 20. construction relative to thework performed than may be had by radial blades. In this case the bladesare longitudinal or extend in the direction of flight, have a doublecurvature, and afford a highly streamlined propulsion means. Withreference to this double curvature a further object of the invention isto strengthen the structure to resist centrifugal force and to give theblades a long leading edge and a large area with reference to the overall dimensions.

Another object of the invention is to provide a blunt nosed air craftgiving a substantial effective area, athwart the direction of travel,with means for removing air from in advance of the blunt surface; thusmaking use of the static pres- 35 sure of air on other parts of thecraft for driving it forward.

The purposes of the invention are accomplished by means of aconstruction diagrammed in the drawing to accentuate its principleswithout undue use of variable details.

In the drawing, Fig. 1 is a plan View of the propeller and its mountingand includes a fragment of a plane with the motor location in thefuselage indicated.

Fig. 2 is a perspective view of the propeller removed from its bearings.

Fig. 3 is a sectional view as indicated by the line: 3-3 on Fig. 1.

Fig. 4 is a fragmentary view of a modified end construction for thepropeller.

This propeller construction is in the general form of a cylinder, exceptthat the blades are given about a ten degree pitch with reference totangents of the encompassing curve. The structure has an open front anda closed rear end 1937, Serial No. 151,189

and operates to draw air inwardly through the open front end and todrive the air outwardly through the spaces between the blades leaving a.Partial vacuum in advance of the closed end of the cylinder. This closedend forms a blunt nose for the bow of the craft and is shielded againstinflow of air by a cylindrical reinforcing flange at its periphery. Theblades preferably do not extend parallel with the axis of the cylinderin one sense, but have helical curves which add to the resistance of thestructure against centrifugal force; increase the area of the blades,and increase the length of the effective air entering edge of theblades.

The propeller rotates in the direction indicated by the arrow in Fig. 2,and the outer face of each blade I 5 is the working face and the for-Ward edges of the blades are nearer the axis of rotation than thetrailing edges for the purpose of throwing the liquid outward andrearward, and in this manner bring about the reaction that drives thecraft forwardly.

The pitch of the blades with reference to the general cylindrical formis varied according to a predetermined diameter and its average rate ofrotation, but for maximum efficiency in high speed work the pitch is inthe neighborhood of ten or eleven degrees to avoid any approach todestructive vibration at high speeds. Proportions are varied accordingto the work performed, and load, with reference to maximum dimensions.

In the example illustrated the cylinder length is approximately threetimes its diameter. Many variants in construction or proportions arepossible without departing from the main purposes or principles of theinvention. Ordinarily with the use of screw propellers an increase inthrust of the propeller may be desired to increase the speed of theplane when overloaded and this is accomplished by pitch changing or bysubstituting a propeller of greater pitch. With the present suctionproducing propulsion means a greater thrust may be attained for thepurposes of increasing speed by substituting a propeller of largerdiameter and greater length without change in pitch.

The drawing indicates a rigid frame structure I providing bearings 2 and3 for the propeller. The propeller shaft 4 is coupled with the crankshaft of a radial engine indicated by the dotted outline 5. 6 representsthe fuselage of a plane and l the supporting wings thereof. Thepropeller construction rigid on shaft 4 includes the hubs 8, 9, and II)respectively connected with the cylindrical air evacuating means byspokes l l and I2, and a disc web I3. Spokes II at their outer ends areattached to an open ring M. The outer ends of spokes I2 are secured tothe central part of the blades I 5 extending from ring M to a peripheralflange IS on web I 3.

Web 13 is shown extending at right angles to the axis of shaft 4 toafford a decisive illustration of an effective area in advance of whichair is removed to cause the propulsion of the craft. In some cases thisweb is of conical form as indicated at I! in Fig. 4, thatis, insteadofextending from hub ID to the ring-shaped iiange l6, it forms acontinuation of that flange and extends to the hub 9. Such cone form isillustrated because it has been used effectively and ispreferred incases where the propeller is sometimes stationary while the craft is inflight, or in the case of sailing vessels equipped with an auxiliary.

In the operation of the propulsion means the effect of the rotatinglongitudinal blades is to throw the air'or water, through which thecraft is traveling outwardly from'within the hollow cylindricalpropeller. The blades also produce a rearward thrust on the air orwater, because of their helical arrangement. The rear end of thepropeller is closed or that space is otherwise blanked off'by the bodyof the craft when the propeller is mounted at the back end thereof. Dueto the vacuum conditions produced within the cylinder, the air or waterattains velocity in the direction of the axis of the cylinder, but isthrown outward, the result being a rearward flow outside of theperiphery of the propeller in the general direction which would becaused by the operation of a screw propeller. Hence this flow of theair, in the case of an air craft, aids in producing a lift at thesupporting surfaces supplemental to the lift caused by the forwardmovement of the plane through the air.

This method of propulsion provides a vacuum tube system operation in theopen. With it the around the cylinder.

2. A propeller of the class described of general hollow cylindrical formand including end supports connected by pitched helical peripheralblades having their working faces on the outside and with their forwardedges nearer theaxis of rotation than the rear edges, and closing meansfor one end of the propeller extending from the axis to the periphery ofthe cylinder.

3.-A propeller of the class described of general hollow cylindrical formand including end supports connected by pitched helical peripheralblades having their working faces on the outside and with their forwardedges nearer the axis of rotation than the rear edges, a conical closingend means for one end of the propeller extending from the axis to theperiphery of the cylinder.

4. A propeller of the class described of general hollow cylindrical formand including end supports connected by pitched helical peripheralblades having their working faces on the outside and with their forwardedges nearer the axis of rotation than the rear edges, a closing endmeans for one end of the propeller extending from the axis to theperiphery of the cylinder, and a peripheral flange or guard associatedwith said end closing means for preventing inward flow of air at thatend of the propeller.

CHARLES M. LEE.

